This invention relates to the field of self-righting lamp fixtures which have a structure that urges the fixture back toward its upright position when tilted away therefrom. In the event of inadvertent contact with the lamp fixture, instead of falling down and causing damage to the fixture the self-righting feature brings it back to its upright position.
Existing lamp fixtures for use at construction sites, camp grounds and other areas where a number of people are involved in active work or play, will normally fall over if accidentally hit. The fixture itself may be damaged. It may also cause damage to other things when knocked over. The present invention provides a solution to those problems by it's self-righting structure with a stabilizing base.
Prior art fixtures of various kinds have included self-righting features. Those known to the inventor include those which are disclosed in the following patents, including the inventor's own U.S. Pat. No. 5,134,555 disclosing a self-positioning lamp fixture.
U.S. Pat. No. 5,001,617 discloses a self balanced, multi position holder which includes structure that will hold the arm of the device at any angle at which it is positioned.
U.S. Pat. No. 4,739,302 discloses a road construction barrier or marker of frusto-conical configuration having a rounded portion near the bottom terminating in a flat bottom wall. The weighted portion or ballast is stated to be rigidly secured in the lower part of the base and is shaped in the form of a cone to produce the value and positioning of the center of gravity desired in that invention.
U.S. Pat. No. 4,117,455 discloses a self-righting roadway marking device having a rounded base of elastomeric material and an upright staff having a light bulb at the top. Wind vanes are secured to the staff to enable the wind to tip and rotate the lighted marking device on its rounded elastomeric base so as to attract more attention to the tipping and rotating light.
U.S. Pat. No. 4,028,543 discloses a baseless lamp fixture having an elongated tubular element with a light bulb at one end and a counterweight at the other, bent in such a way that an intermediate section of the elongated tubular element can be placed on a support member and the counterweight at one end will hold the light bulb at the other end in place.
U.S. Pat. No. 3,863,882 discloses a self balancing support for holding a book, magazine, newspaper or the like at a desired angle. Adjustable bags containing fluent material are connected to the box-like supporting structure having a back panel which can be manipulated in such a way as to hold the supporting structure and back panel at a desired position.
U.S. Pat. No. 1,439,101 discloses a traffic fixture having a pear shaped base, an upright member and a light fixture at the top. A plurality of legs are provided at the bottom to prevent the device from spinning or rotating on its longitudinal axis.
U.S. Pat. No. 1,228,615 discloses a self-righting guide post having a solid base with a slightly curved side wall, a convex top wall and a flat bottom wall, and a slender upright member extending upwardly from the base to which a flag may be attached, or to which a lamp fixture or light bulb may be secured.
U.S. Pat. No. 827,199 discloses a light fixture having a weighted base of generally triangular form.
U.S. Pat. No. 713,364 discloses a buoy having a pear shaped flotation member and a lamp fixture supported thereon, for connection to fishing nets to illuminate the nets and thereby attract fish.
U.K. Patent No. 313,174 discloses a lamp stand having a spherical base with a weight therein and an upright member with a light fixture at the top.
French Patent No. 714,784 discloses a table lamp having an upright support, a light bulb and lamp shade at the upper end, a small sphere or ball of rubber or the like at its lower end to rest on the surface of a table, a semi-circular shaft extending from the small sphere downwardly having a small weighted ball at the lower end of such semi-circular shaft.
Italian Patent No. 312,687 discloses lighting fixtures to outline airport runways which have a rounded base, an upright support member and a light fixture at the top. A battery or transformer is placed in the cavity of the rounded base to provide the electrical energy for the light bulb.
The self-positioning lamp fixture with stabilizing base in accordance with the present invention provides a number of improvements over those devices known to the prior art.
It provides a separate self-righting member or structure to which a separate lamp supporting assembly is connected by fastening screws around the peripheral edges of each component, and by an externally threaded filler neck of the self-righting member being received in the internally threaded recess of the lamp supporting assembly for threaded engagement therein.
The self-righting member is in the form of the segment of a sphere. In one embodiment it is completely solid. In a preferred embodiment it takes the form of a container, having a planar circular top wall lying in a plane which is coincident with or slightly below the equatorial plane of the sphere from which the segment comprising this invention is taken, a planar circular bottom wall lying in a plane below the top wall and above the adjacent pole of the longitudinal axis of such sphere which extends normal to its equatorial plane, and a continuously curved side wall having the same configuration as the corresponding segmented surface portion of such sphere.
Such spherical segment container has a cavity therein bounded by such top, bottom and side walls, opening to the filler passageway through the externally threaded filler neck. This embodiment of the self-righting member makes it possible to use fluid types of weighted material or ballast, such as sand which is poured through the filler neck to completely fill the cavity. The solid top, bottom and side walls of the container hold the sand in place when completely filled, so it does not shift when tilted and does not thereby shift the center of gravity.
Such construction enabling the use of fluid or ballast material has advantages over prior art devices, in that the lamp fixtures may be transported without the heavy ballast material in place. That can be poured into the spherical segment base on the job site or wherever the lamp fixture is to be used. Such construction also simplifies manufacture and sale of the lamp fixtures since the ballast materials can be added later and sold separately.
A closure cap may be provided to close the filler neck, or the roof of the internally threaded cavity of the lamp supporting assembly into which the externally threaded filler neck is screwed may constitute the closure cap to prevent fluid ballast material such as sand from flowing out of the filler neck when the device is tipped to one side.
The planar bottom wall of such spherical segment self-righting member stabilizes the fixture in the upright position. The particular construction in the form of a spherical segment as described herein assures that the center of gravity is below the equilibrium point so when tipped to one side the self-righting member will be rotated by gravitational forces back to its normal upright position.
The improved self-positioning lamp fixture in accordance with this invention provides an additional improvement over prior art devices in that it includes a shock absorbing mechanism for the light bulb socket assembly. A connecting band is provided around the side wall of the socket assembly, having radially extending flanges with apertures to receive one end of coil springs whose opposite ends are secured to the peripheral wall of the lamp supporting member, in the cavity of which the light bulb socket assembly is received. Any shock received by the wall of the lamp supporting member is thereby absorbed in whole or in part by the coil springs.
Further improvements over the prior art will become apparent from the detailed description which follows and from the accompanying drawings.